More globular star clusters found at Milky Way's heart (earthsky.org)

By Deborah Byrd in Space | January 27, 2019

We think of globular clusters as being scattered far from the galaxy’s central regions, in the great spherical halo of our Milky Way. But astronomers are finding them much closer to the galactic center.

Astronomer Denilso Camargo in Brazil emailed EarthSky last week with word of a newly published study, on the discovery of three more ancient globular clusters in the bulge – what these astronomers are calling the heart – of our home galaxy, the Milky Way. The discovery follows a similar one from 2018 by Camargo, in which he announced five globular star clusters near the heart of the Milky Way.

The discovery is unusual because we don’t think of the large, symmetrical globular clusters as residing near the Milky Way’s center. Instead, we think of these ancient clusters – which are thought to contain some of our galaxy’s oldest stars – as belonging to the halo of the galaxy, a more or less spherical region surrounding the galaxy’s center.

Camargo and his co-author – astronomer Dante Minniti in Chile – communicated their discovery a new paper published January 21, 2019, by the Monthly Notices of the Royal Astronomical Society Letters. Camargo wrote:

The two astronomers examined photometric data gathered by NASA’s Wide-field Infrared Survey Explorer (WISE) satellite, as well as data from the Two Micron All-Sky Survey (2MASS). Plus they used data from the European Southern Observatory’s (ESO) VISTA Variables in the Via Lactea extended survey (VVVX) and from the European Space Agency’s Gaia satellite — particularly its amazing second data release, made available last April.
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more: https://earthsky.org/space/globular-clusters-milky-way-heart-bulge-camargo